Stuck in generating world Locating server

A few days ago I was playing with my friends and was exploring The End. When I was going back to home, I found that the area was not loaded correctly and the blocks were invisible to the way back to where the main entrance to the end is. I logged out hoping when I return the blocks would be back. However, I found that I am now stuck in Locating server part of generating a world when I try and log back in. For the past few days now I have been unable to join my friends world. We made a test world to see if I could log into that one and I could. I just now cannot log into the main world we play on.